By Mike Lynch
This is the last full week of summer with astronomical autumn starting Sept. 22.
In the meantime, this week will be lit up nearly 24 hours with sunlight by day and moonlight by night because we have more or less a full moon all week.
The exact night of the full moon is Thursday night to Friday morning. Since it’s close to the autumnal equinox it’s called the harvest moon.
Astronomically, what makes the harvest moon so special is that is rises only about 20 minutes later each night instead of the usual 45 to 50 minutes later each evening, so there isn’t as much of gap between the time the sun goes down and the moon rises
Like any full moon on the rise, the harvest moon sports an orange hue of varying degrees, depending on the clarity of Earth’s atmosphere.
That’s because the moon’s light has to plow through more of Earth’s atmosphere when it’s close to the horizon and that scatters away all but orange and red components of the moon’s light.
When the moon gets higher its light doesn’t have to fight its way through as much atmosphere and it turns white.
The moon also seems a lot larger when it’s rising or setting. That’s just an optical illusion. The same thing happens with the sun and even constellations when they’re close to the horizon.
While you’re getting moonstruck watching the moon rising in the east take a half turn and you’ll see a couple of planets in wonderful celestial hug in the west-southwest sky.
They’re the planets Venus and Saturn. Venus looks like a super bright star with Saturn, not nearly as bright just to the upper right of Venus.
Through even a small telescope you should be able to make out the ring system of Saturn although it’ll be really fuzzy since Saturn is so close to the horizon. Saturn is way, way larger than Venus but is about 10 times farther away. Venus is only about 92 million miles away while Saturn’s nearly a billion miles distant.
In the midnight hour the moon will be beaming in the southern sky. With the naked eye you can easily see the dark areas called maria. They are the volcanic plains of the moon.
The darker maria form “the man on moon.” The white areas are the highlands and mountains.
If you check out our lunar neighbor with a telescope I would highly advise looking though sunglasses. It’s so bright you could earn yourself a big time headache.
Look in the low eastern sky for a cute little cluster of stars known as the Pleiades, or “Seven Little Sisters”..
It’s a cluster of young stars a little more than 400 light-years away, all born together about 100 million years ago.
Early in the morning before sunrise you’ll see the harvest moon heading toward the western horizon and starting to turn orange again.
Meanwhile the eastern half of the sky will be lit up like a Christmas tree with so many bright stars and constellations. I call that part of the sky “Orion and his Gang”: Orion the Hunter with three bright stars in a row that make up his belt.
As a bonus the brightest star you can see in the east is actually the planet Jupiter.
Mike Lynch is an astronomer and professional broadcast meteorologist for WCCO Radio in Minneapolis and is author of “Stars, a Month by Month Tour of the Constellations.” Check his website, www.lynchandthestars.com.
The Everett Astronomical Society: www.everettastro.org/.